sodium 2-{N-[(3,5-difluorophenyl)carbamoyl]ethanehydrazonoyl}nicotinate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

1996-06-21 until 1995-07-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Scientifically valid study, OECD guideline study. Please refer to IUCLID section 13 for read-across justification.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPP 81-3 (Acute inhalation toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Diflufenzopyr

IUPAC Name:

Diflufenzopyr

Constituent 2

Reference substance name:

109293-97-2

EC Number:

600-910-3

Cas Number:

109293-97-2

IUPAC Name:

109293-97-2

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK Ltd, Manston Road, Margate, Kent, England
- Age at study initiation: 8 weeks
- Weight at study initiation: 200 - 300 g
- Housing: The holding cages were made of stainless steel sheet and wire mesh and were suspended on a movable rack.
- Diet: SDS RM1
- Water: tap water
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18 - 24°C
- Humidity: 45 - 78 %

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: A Wright dust generator was used to produce the test atmospheres containing the dust of the test substance
- Exposure chamber volume: 5 L
- Method of holding animals in test chamber: The snout-only exposure chambers were of cylindrical form and made of aluminium alloy. The rats were held for exposure, individually, in polycarbonate restraining tubes attached at one of the ports in the cylindrical section of the chamber. The tube was tapered at one end to allow the snout only to project into the chamber. The other end was closed by insertion of an expanded plastic bung. A push rod passed through the centre of the bung and was adjustable to maintain the position of the rats during exposure.
- Source and rate of air: A supply of clean dried compressed air was connected to the dust generator and the supply pressure was adjusted to give a flow rate of 14 litres per minute measured at the generator outlet nozzle. The total chamber air supply was made up to 15 1/minute with an additional flow of 11/minute into the diluent port of the chamber.
- Method of conditioning air: The test atmosphere was passed through an elutriation column to reduce, by sedimentation, the amount of non-respirable particulate in the test atmosphere.
- Temperature, humidity: 21°C, 25 %

TEST ATMOSPHERE
- Brief description of analytical method used: Five air samples were taken from the chamber during the exposure to determine the concentration of the test substance in the chamber air by chemical analysis. Samples were collected at 30, 60, 120, 180 and 235 minutes following the equilibrium period. Each air sample was withdrawn, at 4 litres per minute, through a weighed glass fibre filter mounted in an open face filter holder. The volume of the air sample was measured with a wet-type gas meter. Two additional air samples were taken during each exposure using a Marple cascade impactor. The samples were taken approximately 1.5 and 3.5 hours after the start of exposure. The material collected on the stages of the sampler was analysed to determine the particle size distribution of the test subsrance in the test atmospheres.
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

Mean analysis concentration: 2.93 mg/L
Mean gravimetric concentration: 3.14 mg/L
Nominal concentration (the nominal concentration is calculated from the amount of the test substance disperrsed and the total volume of air supplied to the exposure system): 17.5 mg/L

No. of animals per sex per dose:

10 animals: 5 males, 5 females

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: daily
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, organ weights, histopathology

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2.93 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality was observed

Clinical signs:

other: During exposure - There were no signs attributable to exposure to the test substance in the test rats. Soiling of the fur with as a consequence of the method of restraint was seen in control and test rats. During observation period - The only sign was exc

Body weight:

Reduced bodyweight or a reduced rate of bodyweight gain was seen in rats exposed to the test substance for 1 day. Subsequently, weight gain was similar to that of control rats.

Gross pathology:

- The lung weight to bodyweight ratios for rats exposed to the test substance were similar to those of the control rats
- There were no internal or external macroscopic abnormalities detected in rats exposed to the test substance
- No treatment-related changes were detected.

Other findings:

Water consumption:
Water consumption was slightly increased for 2 days following exposure to the test substance. Subsequently, water consumption for test rats was similar to that of the control rats.

Any other information on results incl. tables

- The size distribution results from the chemical analysis: 3.5 µm (MMAD) and 80.8 % of respirable particles (< 7 µm)